Move all crates into a crates directory (#1940)

crates/emath/src/vec2.rs

@@ -0,0 +1,463 @@
+use std::ops::{Add, AddAssign, Div, Mul, MulAssign, Neg, Sub, SubAssign};
+
+/// A vector has a direction and length.
+/// A [`Vec2`] is often used to represent a size.
+///
+/// emath represents positions using [`crate::Pos2`].
+///
+/// Normally the units are points (logical pixels).
+#[repr(C)]
+#[derive(Clone, Copy, Default, PartialEq)]
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+#[cfg_attr(feature = "bytemuck", derive(bytemuck::Pod, bytemuck::Zeroable))]
+pub struct Vec2 {
+    /// Rightwards. Width.
+    pub x: f32,
+
+    /// Downwards. Height.
+    pub y: f32,
+}
+
+/// `vec2(x, y) == Vec2::new(x, y)`
+#[inline(always)]
+pub const fn vec2(x: f32, y: f32) -> Vec2 {
+    Vec2 { x, y }
+}
+
+// ----------------------------------------------------------------------------
+// Compatibility and convenience conversions to and from [f32; 2]:
+
+impl From<[f32; 2]> for Vec2 {
+    #[inline(always)]
+    fn from(v: [f32; 2]) -> Self {
+        Self { x: v[0], y: v[1] }
+    }
+}
+
+impl From<&[f32; 2]> for Vec2 {
+    #[inline(always)]
+    fn from(v: &[f32; 2]) -> Self {
+        Self { x: v[0], y: v[1] }
+    }
+}
+
+impl From<Vec2> for [f32; 2] {
+    #[inline(always)]
+    fn from(v: Vec2) -> Self {
+        [v.x, v.y]
+    }
+}
+
+impl From<&Vec2> for [f32; 2] {
+    #[inline(always)]
+    fn from(v: &Vec2) -> Self {
+        [v.x, v.y]
+    }
+}
+
+// ----------------------------------------------------------------------------
+// Compatibility and convenience conversions to and from (f32, f32):
+
+impl From<(f32, f32)> for Vec2 {
+    #[inline(always)]
+    fn from(v: (f32, f32)) -> Self {
+        Self { x: v.0, y: v.1 }
+    }
+}
+
+impl From<&(f32, f32)> for Vec2 {
+    #[inline(always)]
+    fn from(v: &(f32, f32)) -> Self {
+        Self { x: v.0, y: v.1 }
+    }
+}
+
+impl From<Vec2> for (f32, f32) {
+    #[inline(always)]
+    fn from(v: Vec2) -> Self {
+        (v.x, v.y)
+    }
+}
+
+impl From<&Vec2> for (f32, f32) {
+    #[inline(always)]
+    fn from(v: &Vec2) -> Self {
+        (v.x, v.y)
+    }
+}
+
+// ----------------------------------------------------------------------------
+// Mint compatibility and convenience conversions
+
+#[cfg(feature = "mint")]
+impl From<mint::Vector2<f32>> for Vec2 {
+    #[inline]
+    fn from(v: mint::Vector2<f32>) -> Self {
+        Self::new(v.x, v.y)
+    }
+}
+
+#[cfg(feature = "mint")]
+impl From<Vec2> for mint::Vector2<f32> {
+    #[inline]
+    fn from(v: Vec2) -> Self {
+        Self { x: v.x, y: v.y }
+    }
+}
+
+// ----------------------------------------------------------------------------
+
+impl Vec2 {
+    pub const X: Vec2 = Vec2 { x: 1.0, y: 0.0 };
+    pub const Y: Vec2 = Vec2 { x: 0.0, y: 1.0 };
+
+    pub const RIGHT: Vec2 = Vec2 { x: 1.0, y: 0.0 };
+    pub const LEFT: Vec2 = Vec2 { x: -1.0, y: 0.0 };
+    pub const UP: Vec2 = Vec2 { x: 0.0, y: -1.0 };
+    pub const DOWN: Vec2 = Vec2 { x: 0.0, y: 1.0 };
+
+    pub const ZERO: Self = Self { x: 0.0, y: 0.0 };
+    pub const INFINITY: Self = Self::splat(f32::INFINITY);
+
+    #[inline(always)]
+    pub const fn new(x: f32, y: f32) -> Self {
+        Self { x, y }
+    }
+
+    /// Set both `x` and `y` to the same value.
+    #[inline(always)]
+    pub const fn splat(v: f32) -> Self {
+        Self { x: v, y: v }
+    }
+
+    /// Treat this vector as a position.
+    /// `v.to_pos2()` is equivalent to `Pos2::default() + v`.
+    #[inline(always)]
+    pub fn to_pos2(self) -> crate::Pos2 {
+        crate::Pos2 {
+            x: self.x,
+            y: self.y,
+        }
+    }
+
+    /// Safe normalize: returns zero if input is zero.
+    #[must_use]
+    #[inline(always)]
+    pub fn normalized(self) -> Self {
+        let len = self.length();
+        if len <= 0.0 {
+            self
+        } else {
+            self / len
+        }
+    }
+
+    /// Rotates the vector by 90°, i.e positive X to positive Y
+    /// (clockwise in egui coordinates).
+    #[inline(always)]
+    pub fn rot90(self) -> Self {
+        vec2(self.y, -self.x)
+    }
+
+    #[inline(always)]
+    pub fn length(self) -> f32 {
+        self.x.hypot(self.y)
+    }
+
+    #[inline(always)]
+    pub fn length_sq(self) -> f32 {
+        self.x * self.x + self.y * self.y
+    }
+
+    /// Measures the angle of the vector.
+    ///
+    /// ```
+    /// # use emath::Vec2;
+    /// use std::f32::consts::TAU;
+    ///
+    /// assert_eq!(Vec2::ZERO.angle(), 0.0);
+    /// assert_eq!(Vec2::angled(0.0).angle(), 0.0);
+    /// assert_eq!(Vec2::angled(1.0).angle(), 1.0);
+    /// assert_eq!(Vec2::X.angle(), 0.0);
+    /// assert_eq!(Vec2::Y.angle(), 0.25 * TAU);
+    ///
+    /// assert_eq!(Vec2::RIGHT.angle(), 0.0);
+    /// assert_eq!(Vec2::DOWN.angle(), 0.25 * TAU);
+    /// assert_eq!(Vec2::UP.angle(), -0.25 * TAU);
+    /// ```
+    #[inline(always)]
+    pub fn angle(self) -> f32 {
+        self.y.atan2(self.x)
+    }
+
+    /// Create a unit vector with the given CW angle (in radians).
+    /// * An angle of zero gives the unit X axis.
+    /// * An angle of 𝞃/4 = 90° gives the unit Y axis.
+    ///
+    /// ```
+    /// # use emath::Vec2;
+    /// use std::f32::consts::TAU;
+    ///
+    /// assert_eq!(Vec2::angled(0.0), Vec2::X);
+    /// assert!((Vec2::angled(0.25 * TAU) - Vec2::Y).length() < 1e-5);
+    /// ```
+    #[inline(always)]
+    pub fn angled(angle: f32) -> Self {
+        vec2(angle.cos(), angle.sin())
+    }
+
+    #[must_use]
+    #[inline(always)]
+    pub fn floor(self) -> Self {
+        vec2(self.x.floor(), self.y.floor())
+    }
+
+    #[must_use]
+    #[inline(always)]
+    pub fn round(self) -> Self {
+        vec2(self.x.round(), self.y.round())
+    }
+
+    #[must_use]
+    #[inline(always)]
+    pub fn ceil(self) -> Self {
+        vec2(self.x.ceil(), self.y.ceil())
+    }
+
+    #[must_use]
+    #[inline]
+    pub fn abs(self) -> Self {
+        vec2(self.x.abs(), self.y.abs())
+    }
+
+    /// True if all members are also finite.
+    #[inline(always)]
+    pub fn is_finite(self) -> bool {
+        self.x.is_finite() && self.y.is_finite()
+    }
+
+    /// True if any member is NaN.
+    #[inline(always)]
+    pub fn any_nan(self) -> bool {
+        self.x.is_nan() || self.y.is_nan()
+    }
+
+    #[must_use]
+    #[inline]
+    pub fn min(self, other: Self) -> Self {
+        vec2(self.x.min(other.x), self.y.min(other.y))
+    }
+
+    #[must_use]
+    #[inline]
+    pub fn max(self, other: Self) -> Self {
+        vec2(self.x.max(other.x), self.y.max(other.y))
+    }
+
+    /// The dot-product of two vectors.
+    #[inline]
+    pub fn dot(self, other: Self) -> f32 {
+        self.x * other.x + self.y * other.y
+    }
+
+    /// Returns the minimum of `self.x` and `self.y`.
+    #[must_use]
+    #[inline(always)]
+    pub fn min_elem(self) -> f32 {
+        self.x.min(self.y)
+    }
+
+    /// Returns the maximum of `self.x` and `self.y`.
+    #[inline(always)]
+    #[must_use]
+    pub fn max_elem(self) -> f32 {
+        self.x.max(self.y)
+    }
+
+    #[must_use]
+    #[inline]
+    pub fn clamp(self, min: Self, max: Self) -> Self {
+        Self {
+            x: self.x.clamp(min.x, max.x),
+            y: self.y.clamp(min.y, max.y),
+        }
+    }
+}
+
+impl std::ops::Index<usize> for Vec2 {
+    type Output = f32;
+
+    #[inline(always)]
+    fn index(&self, index: usize) -> &f32 {
+        match index {
+            0 => &self.x,
+            1 => &self.y,
+            _ => panic!("Vec2 index out of bounds: {}", index),
+        }
+    }
+}
+
+impl std::ops::IndexMut<usize> for Vec2 {
+    #[inline(always)]
+    fn index_mut(&mut self, index: usize) -> &mut f32 {
+        match index {
+            0 => &mut self.x,
+            1 => &mut self.y,
+            _ => panic!("Vec2 index out of bounds: {}", index),
+        }
+    }
+}
+
+impl Eq for Vec2 {}
+
+impl Neg for Vec2 {
+    type Output = Vec2;
+
+    #[inline(always)]
+    fn neg(self) -> Vec2 {
+        vec2(-self.x, -self.y)
+    }
+}
+
+impl AddAssign for Vec2 {
+    #[inline(always)]
+    fn add_assign(&mut self, rhs: Vec2) {
+        *self = Vec2 {
+            x: self.x + rhs.x,
+            y: self.y + rhs.y,
+        };
+    }
+}
+
+impl SubAssign for Vec2 {
+    #[inline(always)]
+    fn sub_assign(&mut self, rhs: Vec2) {
+        *self = Vec2 {
+            x: self.x - rhs.x,
+            y: self.y - rhs.y,
+        };
+    }
+}
+
+impl Add for Vec2 {
+    type Output = Vec2;
+
+    #[inline(always)]
+    fn add(self, rhs: Vec2) -> Vec2 {
+        Vec2 {
+            x: self.x + rhs.x,
+            y: self.y + rhs.y,
+        }
+    }
+}
+
+impl Sub for Vec2 {
+    type Output = Vec2;
+
+    #[inline(always)]
+    fn sub(self, rhs: Vec2) -> Vec2 {
+        Vec2 {
+            x: self.x - rhs.x,
+            y: self.y - rhs.y,
+        }
+    }
+}
+
+/// Element-wise multiplication
+impl Mul<Vec2> for Vec2 {
+    type Output = Vec2;
+
+    #[inline(always)]
+    fn mul(self, vec: Vec2) -> Vec2 {
+        Vec2 {
+            x: self.x * vec.x,
+            y: self.y * vec.y,
+        }
+    }
+}
+
+/// Element-wise division
+impl Div<Vec2> for Vec2 {
+    type Output = Vec2;
+
+    #[inline(always)]
+    fn div(self, rhs: Vec2) -> Vec2 {
+        Vec2 {
+            x: self.x / rhs.x,
+            y: self.y / rhs.y,
+        }
+    }
+}
+
+impl MulAssign<f32> for Vec2 {
+    #[inline(always)]
+    fn mul_assign(&mut self, rhs: f32) {
+        self.x *= rhs;
+        self.y *= rhs;
+    }
+}
+
+impl Mul<f32> for Vec2 {
+    type Output = Vec2;
+
+    #[inline(always)]
+    fn mul(self, factor: f32) -> Vec2 {
+        Vec2 {
+            x: self.x * factor,
+            y: self.y * factor,
+        }
+    }
+}
+
+impl Mul<Vec2> for f32 {
+    type Output = Vec2;
+
+    #[inline(always)]
+    fn mul(self, vec: Vec2) -> Vec2 {
+        Vec2 {
+            x: self * vec.x,
+            y: self * vec.y,
+        }
+    }
+}
+
+impl Div<f32> for Vec2 {
+    type Output = Vec2;
+
+    #[inline(always)]
+    fn div(self, factor: f32) -> Vec2 {
+        Vec2 {
+            x: self.x / factor,
+            y: self.y / factor,
+        }
+    }
+}
+
+impl std::fmt::Debug for Vec2 {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "[{:.1} {:.1}]", self.x, self.y)
+    }
+}
+
+#[test]
+fn test_vec2() {
+    macro_rules! almost_eq {
+        ($left: expr, $right: expr) => {
+            let left = $left;
+            let right = $right;
+            assert!((left - right).abs() < 1e-6, "{} != {}", left, right);
+        };
+    }
+    use std::f32::consts::TAU;
+
+    assert_eq!(Vec2::ZERO.angle(), 0.0);
+    assert_eq!(Vec2::angled(0.0).angle(), 0.0);
+    assert_eq!(Vec2::angled(1.0).angle(), 1.0);
+    assert_eq!(Vec2::X.angle(), 0.0);
+    assert_eq!(Vec2::Y.angle(), 0.25 * TAU);
+
+    assert_eq!(Vec2::RIGHT.angle(), 0.0);
+    assert_eq!(Vec2::DOWN.angle(), 0.25 * TAU);
+    almost_eq!(Vec2::LEFT.angle(), 0.50 * TAU);
+    assert_eq!(Vec2::UP.angle(), -0.25 * TAU);
+}